Method and device for beamforming

ABSTRACT

A beamformer device is provided for WiFi communication schemes such as IEEE 802.11ax and 802.11be. The beamformer device is configured to: transmit a request to a beamformee device, the request comprising a set of sounding tone indices, the set of sounding tone indices indicating tones for which a report of beamforming information is requested from the beamformee device, wherein the tones are defined according to a first WiFi scheme, wherein the set of sounding tone indices is based on a first tone plan defined by the first WiFi scheme for a partial channel bandwidth and on a second tone plan defined by a second WiFi scheme for a full channel bandwidth. A corresponding beamformee device is further provided.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Application No.PCT/EP2020/073109, filed on Aug. 18, 2020, the disclosure of which ishereby incorporated by reference in its entirety.

TECHNICAL FIELD

The present disclosure relates to techniques for Beamforming. Thedisclosure particularly relates to a beamformer device transmitting arequest with a set of sounding tone indices to a beamformee device, anda beamformee device transmitting a report of beamforming information toa beamformer device. The disclosure further relates to a beamformerdevice receiving a beamforming report from a beamformee device.

BACKGROUND

Compressed Beamforming Report is part of sounding procedure, defined fortransmission of beamforming information from beamformee to beamformer.It is used by IEEE 802.11n/ac/ax versions of WiFi standard, also knownas 11n, 11ac, 11ax. Compressed Beamforming Report consists of MIMO(Multiple-Input Multiple-Output) Control Field that defines variousparameters indication (e.g. Nc, Ng, Codebook size), general feedbackinformation (e.g. average SNR (signal-to-noise ratio) per stream) andper-tone compressed data which includes precoder matrix and per-tone SNR(for MU (multi-user) feedback type).

Starting from 801.11ax sounding may be performed on the entire bandwidth(BW) or part of the BW (single or multiple Resource Allocations—RUs(Resource Units)). Thus, specific set of tone (subcarrier) indices isdefined for sounding of every portion of the supported BW.

IEEE 802.11be, also known as 11be or WiFi6, introduces a larger BW andlarger MIMO size, which require updated feedback parameters, frameformat and also an exact definition of compressed precoder matrix andSNR. Moreover, 802.11be introduces a new tone plan (i.e. a structure offrequency division to basic units, RUs) which implies different tonedefinition to be applied for sounding as well.

SUMMARY

It is the object of this disclosure to provide techniques for improvingperformance of beamforming in advanced communication schemes such as EHT(Extreme High Throughput) WiFi, for example according to IEEE 802.11be.

This object is achieved by the features of the independent claims.Further implementation forms are apparent from the dependent claims, thedescription and the figures.

A basic idea of this disclosure is to apply a new index definition for anew tone plan. The disclosure presents an update for parameters andformats defined by HE (High Efficiency) WiFi, e.g. according to IEEE802.11ax, to include new and extended cases introduced by EHT WiFi, e.g.according to IEEE 802.11be.

The disclosure provides a new/extended definition for the followingfields and parameters:

-   -   New sounding indices definition for BW≥80 MHz;    -   Extended definition of compressed precoder matrix values;    -   Extended definition of SNR values.

In particular, the disclosure introduces a mechanism for adjusting toneindices to 802.11be tone plan.

A new tone plan introduced by 802.11be is for partial BW transmission(including punctured BW) while the full 80 MHz BW assigned to a singleSTA (Station) (or group of STAs) will reuse 802.11ax tone plan. This newtone plan can be defined in a partial BW info field.

The disclosure introduces the following three optional solutions thatwill be described in detail hereinafter:

-   -   Option 1: Introduce a new unified sounding indices set to be        used for all the options (means that the new set should cover        both a new tone plan and 802.11ax tone plan of full BW);    -   Option 2: Introduce a new sounding indices set for partial BW        sounding (by duplication of indices of 20 MHz portion) and add a        center tones indices for full BW sounding;    -   Option 3: Reuse 802.11ax sounding indices set but define which        sounding RUs correspond data RU defined by new tone plan.

A further idea of the disclosure is to define compressed beamformingmatrix values and part of general parameters.

In summary, the disclosure defines indices for measurement and reportedcompressed beamforming precoder matrices for new bandwidth values and anew tone plan introduced by IEEE 802.11be standard. The disclosure alsoprovides an exact definition of compressed precoder matrix form for MIMOschemes larger than 8×8 adopted by IEEE 802.11be.

In order to describe the invention in detail, the following terms,abbreviations and notations will be used:

-   -   BW bandwidth    -   MIMO Multiple-Input Multiple-Output    -   SNR signal-to-noise ratio    -   MU multi-user    -   SU single-user    -   Ng number of tones, tone grouping factor    -   Nc number of spatial streams    -   Na number of angles    -   Nr number of transmit antennas    -   RU resource unit    -   OFDMA Orthogonal Frequency Division Multiple Access    -   STA Station according to WiFi notation    -   AP Access point according to WiFi notation    -   S1 to S4 frequency segments    -   NDP Null Data Packet

Resource Unit (RU) is a unit in OFDMA terminology used in WiFi schemesto denote a group of subcarriers (tones) used in both Downlink (DL) andUplink (UL) transmissions. With OFDMA, different transmit powers may beapplied to different RUs. There are maximum of 9 RUs for 20 MHzbandwidth, 18 in case of 40 MHz and more in case of 80 or 160 MHzbandwidth. The RUs enable an Access Point to allow multi-users to accessit simultaneously and efficiently.

According to a first aspect, the disclosure relates to a beamformerdevice, configured to: transmit a request to a beamformee device, therequest comprising a set of sounding tone indices, the set of soundingtone indices indicating tones for which a report of beamforminginformation is requested from the beamformee device, wherein the tonesare defined according to a first WiFi scheme, wherein the set ofsounding tone indices is based on a first tone plan defined by the firstWiFi scheme for a partial channel bandwidth and on a second tone plandefined by a second WiFi scheme for a full channel bandwidth.

Such a beamformer device can improve performance of beamforming inadvanced communication schemes such as EHT by operating on a novel setof sounding tone indices that is based on the first tone plan forpartial channel bandwidth and on the second tone plan for full channelbandwidth.

The beamformer device (also called beamformer) sends a sounding packetand requests a beamformee device (also called beamformee) to measure achannel on the specific BW which can be an entire BW or part of the BWthat sounding packet is transmitted on.

Afterwards, beamformee is requested to transmit a compressed beamformingreport, which includes beamforming info for those tones that wererequested by beamformer. But the transmission of this report may be onthe entire BW or any part of the BW, not related to reported tones atall.

For example, beamformer transmit sounding packet on 80 MHz and asks toreport on first 10 MHz only, but the report will be transmitted usingentire 80 MHz BW.

In this disclosure, a definition of set of tone indices is given toindicate which part of sounding BF is requested to be reported.

Regarding tone plans and WiFi schemes:

-   -   a. There are two Wifi schemes: 11be (named first scheme) which        supports BW of 80/160/240/320 MHz and flax (named second scheme)        that only 80 MHz is relevant    -   b. For any subset of 80 MHz BW, 11be WiFi scheme defined a new        tone plan (named first tone plan)    -   c. For full 80 MHz BW 11be reuse flax tone plan (named second        tone plan)    -   d. Any BW>80 MHz supported by 11be will use a duplication of 80        MHz tone plan which means that within any 80 MHz segment        rules b. and c. are valid

The first tone plan is partitioned into a plurality of resource units,RU, each RU allocating a respective portion of the channel bandwidth,wherein each RU is partitioned into a plurality of tones to be reported.

The set of sounding tone indices comprises for each RU a start soundingtone index defining a starting tone of the respective RU for reportingthe beamforming information and an end sounding tone index defining anend tone of the respective RU for reporting the beamforming information.

In an exemplary implementation of the beamformer device, the first WiFischeme is 802.11be WiFi, and the second WiFi scheme is 802.11ax WiFi.

This provides the advantage that the beamformer device can be appliedwith IEEE 802.11be WiFi schemes, which provide higher bandwidth andhigher MIMO sizes than current versions of WiFi in order to improveperformance.

In an exemplary implementation of the beamformer device, the first WiFischeme is supporting channel bandwidths of 80 MHz, 160 MHz, 80+80 MHz,240 MHz and 320 MHz.

This provides the advantage that the beamformer device supports suchbandwidths as currently supported by EHT WiFi.

In an exemplary implementation of the beamformer device, the second WiFischeme is supporting a channel bandwidth of 80 MHz.

This provides the advantage that the beamformer device is compliant withcurrent version of IEEE 802.11ax WiFi supporting channel bandwidth of 80MHz.

In an exemplary implementation of the beamformer device, the fullchannel bandwidth is 80 MHz; and the partial channel bandwidth is anysubset of the full channel bandwidth.

This provides the advantage that the beamformer device can be applied ona variety of different bandwidths, either based on the full channelbandwidth or on subsets thereof.

In an exemplary implementation of the beamformer device, the soundingtone indices are based on a new unified sounding index set thatcomprises sounding tone indices for both, the first tone plan for thepartial channel bandwidth and the second tone plan for the full channelbandwidth.

This provides the advantage that the beamformer device can provide newsounding tone indices for bandwidths greater than 80 MHz.

Such a beamformer device supports a solution according to Option 1 asmentioned above. Corresponding tables are described below with respectto FIGS. 5, 6 and 7 .

This implementation describes the rules for option 1 which are that thesounding tone indices are based on a new unified sounding index set thatcomprises sounding tone indices for both, the first tone plan for thepartial channel bandwidth and the second tone plan for the full channelbandwidth. Further explanation of the rules is given in the Figures partof the description with respect to FIGS. 5 to 7 where the differenttables with sounding tone indices are shown for this option 1.

In an exemplary implementation of the beamformer device, the soundingtone indices are based on a new sounding index set for the partialchannel bandwidth and additional center tones indices for the fullchannel bandwidth.

This provides the advantage that the beamformer device can provide newsounding tone indices for a variety of bandwidths, in particularbandwidths greater than 80 MHz.

Such a beamformer device supports a solution according to Option 2 asmentioned above. Corresponding tables are described below with respectto FIGS. 8, 9 and 10 .

This implementation describes the rules for option 2, which are that thesounding tone indices are based on a new sounding index set for thepartial channel bandwidth and additional center tones indices for thefull channel bandwidth. Further explanation of the rules is given in theFigures part of the description with respect to FIGS. 8 to 10 where thedifferent tables with sounding tone indices are shown for this option 2.

In an exemplary implementation of the beamformer device, the soundingtone indices are based on a reuse of the sounding tone indices definedfor resource units of the second tone plan and a definition whichresource units of the second tone plan correspond to resource units ofthe first tone plan.

This provides the advantage that the beamformer device can efficientlyreuse existing sounding tone indices for processing a variety ofbandwidths, in particular bandwidths greater than 80 MHz.

Such a beamformer device supports a solution according to Option 3 asmentioned above. Corresponding tables are described below with respectto FIGS. 11 and 12 .

This implementation describes the rules for option 3, which are that thesounding tone indices are based on a reuse of the sounding tone indicesdefined for resource units of the second tone plan and a definitionwhich resource units of the second tone plan correspond to resourceunits of the first tone plan. Further explanation of the rules is givenin the Figures part of the description with respect to FIGS. 11 and 12where the different tables with sounding tone indices are shown for thisoption 3.

In an exemplary implementation of the beamformer device, the set ofsounding tone indices for a channel bandwidth greater than the fullchannel bandwidth, in particular for a channel bandwidth of 160 MHz,80+80 MHz, 240 MHz or 320 MHz, is based on a duplication of rulesdefined for the set of sounding tone indices within each segment of thefull channel bandwidth.

This provides the advantage that the beamformer device can be appliedwith WiFi schemes of high bandwidth, in particular bandwidths greaterthan 80 MHz.

FIG. 11 described below shows indices definition for bandwidth greaterthan 80 MHz.

Duplication of rules means that rules defined for a specific bandwidthsection are also valid for another bandwidth section. For example, rulesdefined for a bandwidth of 80 MHz can also be applied to the bandwidthsection between 80 MHz and 100 MHz.

In an exemplary implementation of the beamformer device, the request tothe beamformee device indicates a channel bandwidth, wherein theindicated channel bandwidth is a full channel bandwidth defined for thefirst WiFi scheme.

This provides the advantage that the beamformer device is informed ofthe channel bandwidth used by the beamformer device in order toefficiently report its beamforming parameters.

In an exemplary implementation of the beamformer device, the indicatedchannel bandwidth is a full channel bandwidth of 80 MHz, 80+80 MHz, 160MHz, 240 MHz, 320 MHz or any partial bandwidth thereof.

This provides the advantage that the beamformer device can be appliedwith a variety of different bandwidths.

The first WiFi scheme, e.g. 812.11be, defines a plurality of fullchannel bandwidths, e.g. 80 MHz, 80+80 MHz, 160 MHz, 240 MHz, 320 MHz.This full channel bandwidth or a partial channel bandwidth of this fullchannel bandwidth is indicated by the beamformer device. A partialbandwidth is any portion of the full bandwidth, e.g. a partial bandwidthof 80 MHz full bandwidth may be 20 MHz or 40 MHz or 60 MHz or 77 MHz orany other portion of 80 MHz. For example, a partial bandwidth of 320 MHzfull bandwidth may be any portion of 320 MHz, e.g. 80 MHz or 160 MHz or200 MHz or 300 MHz or 319 MHz, or any other portion of 320 MHz.

In an exemplary implementation of the beamformer device, the set ofsounding tone indices is defined per channel bandwidth and per number oftones, Ng, in particular for Ng=4 and Ng=16.

This provides the advantage that the beamformer device is flexible withrespect to the channel bandwidth and the number of tones.

According to a second aspect, the disclosure relates to a method forrequesting beamforming information, the method comprising: transmitting,by a beamformer device, a request to a beamformee device, the requestcomprising a set of sounding tone indices, the set of sounding toneindices indicating tones for which a report of beamforming informationis requested from the beamformee device, wherein the tones are definedaccording to a first WiFi scheme, wherein the set of sounding toneindices is based on a first tone plan defined by the first WiFi schemefor a partial channel bandwidth and on a second tone plan defined by asecond WiFi scheme for a full channel bandwidth; and receiving thereport of beamforming information from the beamformee device based onthe set of sounding tone indices.

This method corresponds to the beamformer device described above for thefirst aspect of the disclosure.

Such a method for requesting beamforming information can improveperformance of beamforming in advanced communication schemes such as EHTby operating on a novel set of sounding tone indices that is based onthe first tone plan for partial channel bandwidth and on the second toneplan for full channel bandwidth.

The first WiFi scheme may be 802.11be WiFi, particularly supportingchannel bandwidths of 80 MHz, 160 MHz, 80+80 MHz, 240 MHz and 320 MHz.the second WiFi scheme may be 802.11ax WiFi, particularly supporting achannel bandwidth of 80 MHz.

According to a third aspect, the disclosure relates to a beamformeedevice, configured to: transmit a report of beamforming information to abeamformer device based on a set of sounding tone indices received fromthe beamformer device, wherein the set of sounding tone indices areindicating tones for which a report of beamforming information isrequested from the beamformee device, wherein the tones are definedaccording to a first WiFi scheme, wherein the set of sounding toneindices is based on a first tone plan defined by the first WiFi schemefor a partial channel bandwidth and on a second tone plan defined by asecond WiFi scheme for a full channel bandwidth.

Such a beamformee device can improve performance of beamforming inadvanced communication schemes such as EHT by operating on a novel setof sounding tone indices that is based on the first tone plan forpartial channel bandwidth and on the second tone plan for full channelbandwidth.

This beamformee device has the same features as the beamformer device ofthe first aspect described above. But it is the entity that receives therequest from the beamformer device and transmits the report tobeamformer device.

The first WiFi scheme may be 802.11be WiFi, particularly supportingchannel bandwidths of 80 MHz, 160 MHz, 80+80 MHz, 240 MHz and 320 MHz.The second WiFi scheme may be 802.11ax WiFi, particularly supporting achannel bandwidth of 80 MHz.

According to a fourth aspect, the disclosure relates to a method forreporting beamforming information, the method comprising: transmitting,by a beamformee device, a report of beamforming information to abeamformer device based on a set of sounding tone indices received fromthe beamformer device, wherein the set of sounding tone indices areindicating tones for which a report of beamforming information isrequested from the beamformee device, wherein the tones are definedaccording to a first WiFi scheme, wherein the set of sounding toneindices is based on a first tone plan defined by the first WiFi schemefor a partial channel bandwidth and on a second tone plan defined by asecond WiFi scheme for a full channel bandwidth.

Such a method for reporting beamforming information can improveperformance of beamforming in advanced communication schemes such as EHTby operating on a novel set of sounding tone indices that is based onthe first tone plan for partial channel bandwidth and on the second toneplan for full channel bandwidth.

This method corresponds to the beamformee device described above for thethird aspect of the disclosure.

The first WiFi scheme may be 802.11be WiFi, particularly supportingchannel bandwidths of 80 MHz, 160 MHz, 80+80 MHz, 240 MHz and 320 MHz.The second WiFi scheme may be 802.11ax WiFi, particularly supporting achannel bandwidth of 80 MHz.

According to a fifth aspect, the disclosure relates to a beamformerdevice, configured to: receive a beamforming report from a beamformeedevice, wherein the beamforming report comprises a compressed precodermatrix; and reconstruct a precoder matrix reported by the beamformeedevice based on the compressed precoder matrix, wherein the compressedprecoder matrix is defined by a set of angles in a specific order thatimplies a sequence of mathematical operations to be applied on a unitmatrix to reconstruct the precoder matrix, wherein the set of angles isdetermined based on an extension of a given formula specified for anumber of transmit antennas and a number of spatial streams supported bya second WiFi scheme, in particular 802.11ax WiFi, to a number oftransmit antennas, Nr, and a number of spatial streams, Nc, supported bya first WiFi scheme, in particular 802.11be WiFi.

Such a beamformer device can improve performance of beamforming inadvanced communication schemes such as EHT by using the extended formulawhich is extended with respect to number of transmit antennas and numberof spatial streams as supported by EHT.

In an exemplary implementation of the beamformer device, the extensionof the given formula is specified for values of 8<Nr≤16 and values of1≤Nc≤16 corresponding to matrices from 9×1 to 16×16.

This provides the advantage that higher MIMO sizes can be implementedand optimally controlled. I.e. the beamformer device can be applied indenser populated environments having higher number of stations.

In an exemplary implementation of the beamformer device, the beamformingreport comprises SNR values of spatial streams reported by thebeamformee device, wherein each reported i-th SNR value, in particularfor i>8, corresponds to an SNR that results from applying an i-th columnof the reported precoder matrix by the beamformer device.

This provides the advantage that SNR values can be better controlled.

In an exemplary implementation of the beamformer device, the beamformingreport comprises SNR values of spatial streams for MIMO schemes largerthan 8×8.

This provides the advantage that the beamformer device can be appliedwith spatial streams of high MIMO size and hence improve communicationquality.

According to a seventh aspect, the disclosure relates to a computerprogram product including computer executable code or computerexecutable instructions that, when executed, causes at least onecomputer to execute the method according to the aspects above. Such acomputer program product may include a non-transient readable storagemedium storing program code thereon for use by a processor, the programcode comprising instructions for performing the methods or the computingblocks as described hereinafter.

According to an eighth aspect, the disclosure relates to a beamformerdevice (110), configured to transmit a request of partial bandwidth, BW,for sounding feedback to a beamformee device (120), the requestedpartial BW for sounding feedback comprising a partial BW type,indicating the BW to be used for sounding feedback.

In an exemplary implementation of the beamformer device according to theeighth aspect the partial BW type can be 20 MHz, 40 MHz or n×80 MHz,wherein n is an integer equal or larger than 1.

In an exemplary implementation of the beamformer device according to theeighth aspect the requested partial BW for sounding feedback iscomprised in a Partial BW Info field.

In an exemplary implementation of the beamformer device according to theeighth aspect the Partial BW Info Field comprises 6 bits.

In an exemplary implementation of the beamformer device according to theeighth aspect the 2 least significant bits of the Partial BW Info Fieldindicate the type of partial BW.

In the following we show an exemplary mapping between the two leastsignificant bits B0, B1 of the Partial BW Info Field and the requestedpartial BW. Any other mapping is also possible.

B0 B1 Requested partial BW Resource Units 0 0 20 MHz RU242 0 1 40 MHzRU484 1 0 n x 80 MHz (80/160/240/320 MHz) 1 1 Reserved Reserved

In an exemplary implementation of the beamformer device according to theeighth aspect the 4 most significant bits of the Partial BW Info Fieldindicate a specific BW corresponding the indicated partial BW type.

In the following we show an exemplary mapping between the four mostsignificant bits B2, B3, B4 and B5 of the Partial BW Info Field and thelocation of the resource units. Any other mapping is also possible.

B2 B3 B4 B5 Location of the Resource Units 0 0 0 0 RU located at thelowest frequency X X X X Reserved 1 1 1 1 RU located at the highestfrequency

In an exemplary implementation of the beamformer device according to theeighth aspect if a partial BW type of 20 MHz is signaled, the 4 mostsignificant bits of the Partial BW Info Field of the Partial BW InfoField indicate k-th RU242, where k is an integer equal or larger than 0.In particular, k may be an integer from 0 to 15.

In an exemplary implementation of the beamformer device according to theeighth aspect if a partial BW type of 40 MHz is signaled, the 4 mostsignificant bits of the Partial BW Info Field indicate k-th RU484, wherek is an integer equal or larger than 0, in particular from 0 to 7, ork-th RU242, where k is an integer equal or larger than 0. In particular,k may be an integer from 0 to 15.

In an exemplary implementation of the beamformer device according to theeighth aspect if a partial BW type of n×80 MHz is signaled, the 4 mostsignificant bits of the Partial BW Info Field indicate a bitmap for 4segments of 80 MHz, wherein an indicated ‘1’ means 80 MHz is requestedfor sounding feedback.

In an exemplary implementation of the beamformer device according to theeighth aspect if a partial BW type of 20 MHz is signaled, for indicatedk-th RU242, tone indices defined for k RU242 are used, wherein k is aninteger equal or larger than 0.

In an exemplary implementation of the beamformer device according to theeighth aspect if a partial BW type of 40 MHz is signaled, for indicatedk-th RU484, tone indices defined for 2×k and 2×k+1 RU242 are used andfor indicated k-th RU242, tone indices defined for k and k+1 RU242 areused, wherein k is an integer equal or larger than 0.

In an exemplary implementation of the beamformer device according to theeighth aspect if a partial BW type of n×80 MHz is signaled, tone indicesdefined for 4*k, 4*k+1, 4*k+2, 4*k+3 RU242 are used, wherein n and k areinteger equal or larger than 0.

BRIEF DESCRIPTION OF THE DRAWINGS

Further embodiments of the invention will be described with respect tothe following figures, in which:

FIG. 1 shows a schematic diagram 100 illustrating a sounding procedure100 defined for transmission of beamforming information betweenbeamformer 110 and beamformee 120;

FIG. 2 shows a tone plan 200 defined by IEEE 802.11ax standard withresource unit locations of 80 MHz;

FIG. 3 shows a resource unit index table 300 with start and end indicesdefinition for Sounding in IEEE 802.11ax standard;

FIG. 4 shows a tone plan 400 defined by IEEE 802.11be standard for 80MHz;

FIG. 5 shows a resource unit index table 500 with RU start and endindices definition for Unified Indices Set of Ng=4 and 80 MHz bandwidthaccording to the first optional solution of the disclosure;

FIG. 6 shows a resource unit index table 600 with RU start and endindices definition for Unified Indices Set of Ng=16 and 80 MHz bandwidthaccording to the first optional solution of the disclosure;

FIG. 7 shows a superset of subcarrier indices 700 for compressedbeamforming of 80 MHz bandwidth according to the first optional solutionof the disclosure;

FIG. 8 shows a resource unit index table 800 with RU start and endindices definition for Partial bandwidth of Ng=4 and 80 MHz bandwidthaccording to the second optional solution of the disclosure;

FIG. 9 shows a resource unit index table 900 with RU start and endindices definition for Partial bandwidth of Ng=16 and 80 MHz bandwidthaccording to the second optional solution of the disclosure;

FIG. 10 shows a superset of subcarrier indices 1000 for partialbandwidth compressed beamforming of 80 MHz bandwidth according to thesecond optional solution of the disclosure;

FIG. 11 shows a cross-reference table 1100 for resource unit indices of80 MHz bandwidth according to the third optional solution of thedisclosure;

FIG. 12 shows an indices definition table 1200 for bandwidths greaterthan 80 MHz according to the third optional solution of the disclosure;

FIG. 13 shows an exemplary angles definition table, T9, 1300illustrating the order of angles in the compressed beamforming feedbackmatrix subfield for a number of transmit antennas Nr=9 according to thedisclosure;

FIG. 14 shows an exemplary angles definition table, T10, 1400illustrating the order of angles in the compressed beamforming feedbackmatrix subfield for a number of transmit antennas Nr=10 according to thedisclosure;

FIGS. 15 and 16 show an exemplary angles definition table, T11a, T11billustrating the order of angles in the compressed beamforming feedbackmatrix subfield for a number of transmit antennas Nr=11 according to thedisclosure, the first part T11a, 1500 of the table is shown in FIG. 15and the second part T11b, 1600 of the table is shown in FIG. 16 ;

FIGS. 17 and 18 show an exemplary angles definition table, T12a, T12billustrating the order of angles in the compressed beamforming feedbackmatrix subfield for a number of transmit antennas Nr=12 according to thedisclosure, the first part T12a, 1700 of the table is shown in FIG. 17and the second part T12b, 1800 of the table is shown in FIG. 18 ;

FIGS. 19 and 20 show an exemplary angles definition table, T13a, T13billustrating the order of angles in the compressed beamforming feedbackmatrix subfield for a number of transmit antennas Nr=13 according to thedisclosure, the first part T13a, 1900 of the table is shown in FIG. 19and the second part T13b, 2000 of the table is shown in FIG. 20 ;

FIGS. 21 and 22 show an exemplary angles definition table, T14a, T14billustrating the order of angles in the compressed beamforming feedbackmatrix subfield for a number of transmit antennas Nr=14 according to thedisclosure, the first part T14a, 2100 of the table is shown in FIG. 21and the second part T14b, 2200 of the table is shown in FIG. 22 ;

FIGS. 23 and 24 show an exemplary angles definition table, T15a, T15billustrating the order of angles in the compressed beamforming feedbackmatrix subfield for a number of transmit antennas Nr=15 according to thedisclosure, the first part T15a, 2300 of the table is shown in FIG. 23and the second part T15b, 2400 of the table is shown in FIG. 24 ;

FIGS. 25, 26 and 27 show an exemplary angles definition table, T16a,T16b, T16c illustrating the order of angles in the compressedbeamforming feedback matrix subfield for a number of transmit antennasNr=16 according to the disclosure, the first part T16a, 2500 of thetable is shown in FIG. 25 , the second part T16b, 2600 of the table isshown in FIG. 26 and the third part T16c, 2700 of the table is shown inFIG. 27 ;

FIG. 28 shows a schematic diagram of a method 2800 for requestingbeamforming information according to the disclosure; and

FIG. 29 shows a schematic diagram of a method 2900 for reportingbeamforming information according to the disclosure.

FIG. 30 shows a schematic diagram of a Partial BW Info Field.

FIG. 31 shows a schematic diagram of a modified STA Info Subfield.

DETAILED DESCRIPTION OF EMBODIMENTS

In the following detailed description, reference is made to theaccompanying drawings, which form a part thereof, and in which is shownby way of illustration specific aspects in which the disclosure may bepracticed. It is understood that other aspects may be utilized andstructural or logical changes may be made without departing from thescope of the present disclosure. The following detailed description,therefore, is not to be taken in a limiting sense, and the scope of thepresent disclosure is defined by the appended claims.

It is understood that comments made in connection with a describedmethod may also hold true for a corresponding device or systemconfigured to perform the method and vice versa. For example, if aspecific method step is described, a corresponding device may include aunit to perform the described method step, even if such unit is notexplicitly described or illustrated in the figures. Further, it isunderstood that the features of the various exemplary aspects describedherein may be combined with each other, unless specifically notedotherwise.

The methods, devices and systems described herein may be implemented inwireless communication schemes, in particular communication schemesaccording to WiFi communication standards according to IEEE 802.11, inparticular 802.11n/ac/ax versions of the WiFi standard and 802.11beversion of the WiFi standard. The described devices may includeintegrated circuits and/or passives and may be manufactured according tovarious technologies. For example, the circuits may be designed as logicintegrated circuits, analog integrated circuits, mixed signal integratedcircuits, optical circuits, memory circuits and/or integrated passives.

The devices described herein may be configured to transmit and/orreceive radio signals. Radio signals may be or may include radiofrequency signals radiated by a radio transmitting device (or radiotransmitter or sender). However, devices described herein are notlimited to transmit and/or receive radio signals, also other signalsdesigned for transmission in deterministic communication networks may betransmitted and/or received.

The devices and systems described herein may include processors orprocessing devices, memories and transceivers, i.e. transmitters and/orreceivers. The term “processor” or “processing device” describes anydevice that can be utilized for processing specific tasks (or blocks orsteps). A processor or processing device can be a single processor or amulti-core processor or can include a set of processors or can includemeans for processing. A processor or processing device can processsoftware or firmware or applications etc.

FIG. 1 shows a schematic diagram 100 illustrating a sounding procedure100 defined for transmission of beamforming information betweenbeamformer 110 and beamformee 120.

Beamforming depends on channel calibration procedures, called channelsounding in the 802.11 WiFi standard, to determine how to radiate energyin a preferred direction.

Channel sounding 100 consists of three major steps:

-   -   In a first step, the beamformer 110 begins the process by        transmitting a Null Data Packet (NDP) Announcement frame 111,        which is used to gain control of the channel and identify        beamformees. Beamformees 120 will respond to the NDP        Announcement 111, while all other stations will simply defer        channel access until the sounding sequence is complete.    -   In a second step, the beamformer 110 follows the NDP        Announcement 111 with a null data packet (NDP) 112. The value of        an NDP 112 is that the receiver can analyze the OFDM training        fields to calculate the channel response, and therefore the        steering matrix. For multi-user transmissions, multiple NDPs 112        may be transmitted.    -   In a third step, the beamformee 120 analyzes the training fields        in the received NDP 112 and calculates a feedback matrix. The        feedback matrix which is reported by the beamformee 120 in        compressed beamforming report 121 enables the beamformer 110 to        calculate the steering matrix to direct transmissions toward the        beamformee 120.

The sounding procedure 100 may be performed on the entire bandwidth orpart of the BW. A specific set of tone (subcarrier) indices is definedfor sounding of every portion of the supported bandwidth. IEEE 802.11beWiFi introduces a larger bandwidth and larger MIMO size which requireupdated feedback parameters, frame format and also an exact definitionof compressed precoder matrix and SNR. Moreover, 802.11be introduces anew tone plan which implies different tone definition to be applied forsounding as well.

In the following, a beamformer device 110 and a beamformee device 120are described which improve performance of beamforming in advancedcommunication schemes such as EHT WiFi, for example according to IEEE802.11be.

Such a novel beamformer device 110 is configured to transmit a request111 (e.g. by NDP Announcement) to a beamformee device 120. The requestcomprises a set of sounding tone indices indicating tones for which areport 121 of beamforming information is requested from the beamformeedevice 120. The tones are defined according to a first WiFi scheme. Theset of sounding tone indices is based on a first tone plan (e.g. a firsttone plan 400 as shown in FIG. 4 ) defined by the first WiFi scheme fora partial channel bandwidth and on a second tone plan (e.g. a secondtone plan 200 as shown in FIG. 2 ) defined by a second WiFi scheme for afull channel bandwidth.

The first WiFi scheme may be 802.11be WiFi, and the second WiFi schememay be 802.11ax WiFi.

The first WiFi scheme may support channel bandwidths of 80 MHz, 160 MHz,80+80 MHz, 240 MHz and 320 MHz.

The second WiFi scheme may support a channel bandwidth of 80 MHz.

The full channel bandwidth may be 80 MHz, for example. The partialchannel bandwidth may be any subset of the full channel bandwidth, forexample.

According to the first optional solution described above, the soundingtone indices may be based on a new unified sounding index set, e.g. aset 500, 600, 700 as described below with respect to FIGS. 5, 6 and 7 ,that comprises sounding tone indices for both, the first tone plan 400for the partial channel bandwidth and the second tone plan 200 for thefull channel bandwidth.

According to the second optional solution described above, the soundingtone indices may be based on a new sounding index set, e.g. a set 800,900, 1000 as described below with respect to FIGS. 8, 9 and 10 , for thepartial channel bandwidth and additional center tones indices for thefull channel bandwidth.

According to the third optional solution described above, the soundingtone indices may be based on a reuse of the sounding tone indices, e.g.the sounding tone indices 1100, 1200 described below with respect toFIGS. 11 and 12 , defined for resource units of the second tone plan 200and a definition which resource units of the second tone plan 200correspond to resource units of the first tone plan 400.

The set of sounding tone indices for a channel bandwidth greater thanthe full channel bandwidth, for example for a channel bandwidth of 160MHz, 80+80 MHz, 240 MHz or 320 MHz, may be based on a duplication ofrules defined for the set of sounding tone indices within each segmentof the full channel bandwidth, e.g. as described below with respect toFIGS. 11 and 12 .

The request to the beamformee device 120 may indicate a channelbandwidth. The indicated channel bandwidth may be a full channelbandwidth defined for the first WiFi scheme.

For example, the indicated channel bandwidth may be a full channelbandwidth of 80 MHz, 80+80 MHz, 160 MHz, 240 MHz, 320 MHz or any partialbandwidth thereof.

The set of sounding tone indices may be defined per channel bandwidthand per number of tones, Ng, for example for Ng=4 and Ng=16.

Such a novel beamformee device 120 shown in FIG. 1 is configured totransmit a report 121 of beamforming information to a beamformer device110 based on a set of sounding tone indices received from the beamformerdevice 110. The set of sounding tone indices are indicating tones forwhich a report of beamforming information is requested from thebeamformee device 120. The tones are defined according to a first WiFischeme. The set of sounding tone indices is based on a first tone plandefined by the first WiFi scheme for a partial channel bandwidth and ona second tone plan defined by a second WiFi scheme for a full channelbandwidth.

As described above, a further idea of the disclosure is to definecompressed beamforming matrix values and part of general parameters.

This can be implemented by a novel beamformer device 110, configured to:receive a beamforming report 121 from a beamformee device 120, whereinthe beamforming report 121 comprises a compressed precoder matrix; andreconstruct a precoder matrix reported by the beamformee device 120based on the compressed precoder matrix. The compressed precoder matrixis defined by a set of angles in a specific order that implies asequence of mathematical operations to be applied on a unit matrix toreconstruct the precoder matrix. The set of angles is determined basedon an extension of a given formula specified for a number of transmitantennas and a number of spatial streams supported by a second WiFischeme, for example 802.11ax WiFi, to a number of transmit antennas, Nr,and a number of spatial streams, Nc, supported by a first WiFi scheme,for example 802.11be WiFi.

The specific formula may be given in section 20.3.12.3.6 of 802.11nstandard and defined by each version of 802.11 with respect to allowedNr and Nc values.

Specific values for the set of angles are given in tables T9, T10,T11a/b, T12a/b, T13a/b, T14a/b, T15a/b and T16a/b/c for differentnumbers of transmit antennas, Nr, as shown in FIGS. 13 to 27 .

The extension of the given formula may be specified for values of8<Nr≤16 and values of 1≤Nc≤16 corresponding to matrices from 9×1 to16×16.

The beamforming report 121 may comprise SNR values of spatial streamsreported by the beamformee device 120. Each reported i-th SNR value, inparticular for i>8, corresponds to an SNR that results from applying ani-th column of the reported precoder matrix by the beamformer device120.

The beamforming report 121 may comprise SNR values of spatial streamsfor MIMO schemes larger than 8×8.

FIG. 2 shows a tone plan 200 defined by IEEE 802.11ax standard withresource unit locations of 80 MHz, also denoted hereinafter as secondtone plan.

802.11ax standard introduced OFDMA format where the entire bandwidth isdivided into blocks defined as Resource Units (RUs). Transmitted signalmay be combined of multiple allocations where different RUs allocatedfor different stations. The RU sizes are defined by number of frequencytones and can be of 26/52/106/242/484/996 tones as shown in FIG. 2 . Thebandwidth of 80 MHz includes 9 RUs of 26, 4 RUs of 52 and so on asdepicted in FIG. 2 .

FIG. 3 shows a resource unit index table 300 with start (S) and end (E)indices definition for Sounding in IEEE 802.11ax standard.

Sounding procedure (as shown in FIG. 1 ) defines sampling of frequencyfor channel measurement and report that can be every 4 or 16 (Ng) tones.In order to align between RUs definition and sounding samplingparameter, an explicit definition of set of tone indices is provided bystandard for sounding procedure.

For each RU a start sounding tone index, i.e. RU Index Start, (denotedby S in FIG. 3 ) and end sounding tone index, i.e. RU Index End,(denoted by E in FIG. 3 ) is defined to ensure all the tones of RUs arecovered. Sounding start/end indices are different from regular toneindices used for data transmission, see example in FIG. 3 . The set ofindices is defined per bandwidth (in FIG. 3 shown for bandwidths of 20MHz, 40 MHz, 80 MHz, 160 MHz, and 80+80 MHz) and per Ng value

FIG. 4 shows a tone plan 400 defined by IEEE 802.11be standard for 80MHz, also denoted hereinafter as first tone plan.

The IEEE 802.11be standard introduces the three main changes in terms ofbandwidth over 802.11ax: A larger BW is supported of 240 MHz and 320MHz. A new tone plan 400 as illustrated in FIG. 4 is defined for 80 MHzbandwidth for all the cases except the case when full bandwidth isallocated to a single station (STA) (or a group of STAs). All thebandwidths greater than 80 MHz are defined as a duplication of 80 MHzbandwidth.

Indices defined by sounding procedure of 802.11ax (see FIG. 1 ) are nolonger aligned to locations of RUs as given by the new tone plan 400.Thus, sounding procedure definitions need to be updated to follow thenew tone plan 400 and also a new rule of duplication of the tone plan400 for bandwidth.

FIGS. 5, 6 and 7 describe the solution according to option 1 for the newindex definition for the new tone plan. Option 1 introduces a newunified sounding indices set to be used for all the options, that meansthat the new set covers both a new tone plan and 802.11ax tone plan offull BW.

FIG. 5 shows a resource unit index table 500 with RU start and endindices definition for Unified Indices Set of Ng=4 and 80 MHz bandwidth.FIG. 6 shows a resource unit index table 600 with RU start and endindices definition for Unified Indices Set of Ng=16 and 80 MHzbandwidth. FIG. 7 shows a corresponding superset of subcarrier indices700 for compressed beamforming of 80 MHz bandwidth.

The unified indices set is a new set introduced for entire 80 MHzbandwidth while all the RUs of 26 tones are covered by single RUStart/End index pair and in addition center tones of 996 RU are coveredas additional tones.

The rules for applying this option 1 are as follows:

-   -   RU Start/End Index corresponds to 26 RUs defined by new tone        plan of 80 MHz bandwidth (see FIG. 4 );    -   For Ng=4, if indicated RUs cover entire bandwidth, indices of        center portion are used as well.

The indices for Ng=4 and Ng=16 are shown in FIGS. 5 and 6 ,respectively.

And the superset of indices for 80 MHz is shown in FIG. 7 .

FIGS. 8, 9 and 10 describe the solution according to option 2 for thenew index definition for the new tone plan. Option 2 introduces a newsounding indices set for partial bandwidth sounding, by duplication ofindices of 20 MHz portion, and adding center tones indices for full BWsounding.

FIG. 8 shows a resource unit index table 800 with RU start and endindices definition for Partial bandwidth of Ng=4 and 80 MHz bandwidth.FIG. 9 shows a resource unit index table 900 with RU start and endindices definition for Partial bandwidth of Ng=16 and 80 MHz bandwidth.FIG. 10 shows a corresponding superset of subcarrier indices 1000 forpartial bandwidth compressed beamforming of 80 MHz bandwidth.

In this Option 2, a set of indices for partial BW sounding is defined.The indices are defined as a duplication of 20 MHz portions. The rulesfor applying this options are as follows:

-   -   RU Start/End Index corresponds to 26 RUs defined by new tone        plan of 80 MHz BW (see FIG. 4 );    -   If indicated RUs cover entire bandwidth, use additional center        portion indices.

The indices for Ng=4 and Ng=16 are shown in FIGS. 8 and 9 ,respectively.

And the superset of indices for partial bandwidth compressed beamforming80 MHz is shown in FIG. 10 .

FIGS. 11 and 12 describe the solution according to option 3 for the newindex definition for the new tone plan. Option 3 introduces reusing802.11ax sounding indices set but defining which sounding RUs corresponddata RU defined by new tone plan.

FIG. 11 shows a cross-reference table 1100 for resource unit indices of80 MHz bandwidth according to the third optional solution of thedisclosure.

In this option 3, the definition of indices in 802.11ax standard isreused (see Tables 9-93c-d of IEEE 802.11ax). The corresponding indicesfor the new tone plan (see FIG. 4 ) are given in FIG. 11 . This meansthat every 26 RU indicated for sounding use indexes defined in 802.11axusing RUs indices as shown in FIG. 11 .

FIG. 12 shows an indices definition table 1200 for bandwidths greaterthan 80 MHz according to the third optional solution of the disclosure.

IEEE 802.11be defines that the tone plan for every bandwidth greaterthan 80 MHz will be a duplication of 80 MHz. Every suggested option ofnew indices set is applicable for a bandwidth greater than 80 MHz as aduplication of indices for multiple 80 MHz segments, both for partial BWsounding and full BW sounding.

Thus, the indices for compressed beamforming of a bandwidth greater than80 MHz can be given as depicted in FIG. 12 . S1 corresponds to lowerfrequency segment, S2-S4 correspond to frequency segments in ascendingorder.

As described above, a further idea of the disclosure is to definecompressed beamforming matrix values and part of general parameters.

This can be implemented by a novel beamformer device 110 as describedabove with respect to FIG. 1 . This novel beamformer device 110 isconfigured to receive a beamforming report 121 from a beamformee device120. The beamforming report 121 comprises a compressed precoder matrix.The novel beamformer device 110 is configured to reconstruct a precodermatrix reported by the beamformee device 120 based on the compressedprecoder matrix. The compressed precoder matrix is defined by a set ofangles in a specific order that implies a sequence of mathematicaloperations to be applied on a unit matrix to reconstruct the precodermatrix. The set of angles is determined based on an extension of a givenformula specified for a number of transmit antennas and a number ofspatial streams supported by a second WiFi scheme, for example 802.11axWiFi, to a number of transmit antennas, Nr, and a number of spatialstreams, Nc, supported by a first WiFi scheme, for example 802.11beWiFi. The specific formula may be given in section 20.3.12.3.6 of802.11n standard and defined by each version of 802.11 with respect toallowed Nr and Nc values.

Specific values for the set of angles are given in tables T9, T10,T11a/b, T12a/b, T13a/b, T14a/b, T15a/b and T16a/b/c for differentnumbers of transmit antennas, Nr, as shown in FIGS. 13 to 27 .

The compressed precoder matrix is defined by a set of angles in aspecific order that implies a sequence of mathematical operations thatbeamformer should apply on the unit matrix to reconstruct precodermatrix reported by beanformee. The angles are obtained by the formulagiven in section 20.3.12.3.6 of IEEE 802.11n standard and defined byeach version of IEEE 802.11 with respect to allowed Nr and Nc values.The definition includes Na (number of angles) and also the exact orderof angles for feedback report transmission. Thus, the disclosure extendsthis definition for schemes larger than 8×8 as defined in IEEE 802.11be.The full definition of all the angles for all the possible MIMO size isshown below with respect to FIGS. 13 to 27 .

The beamforming report includes also SNR values for the reported spatialstreams. In Single-User feedback format only average SNR (over entirebandwidth) is reported, while in Multi-User format, both average SNR andSNR per-tone are reported. The number of SNR values equal Nc while thei-th SNR value corresponds to expected SNR if beamformer applies a i-thcolumn of the reported precoder matrix. This scheme can be extended forNc>8 according to the following rule:

-   -   For any i>8, reported i-th SNR value (average and per-tone)        corresponds to an expected SNR if beamformer applies a i-th        column of the reported precoder matrix.

FIG. 13 shows an exemplary angles definition table, T9, 1300illustrating the order of angles in the compressed beamforming feedbackmatrix subfield for a number of transmit antennas Nr=9.

The angles definition table, T9, 1300 defines the order of angles in thecompressed beamforming feedback matrix subfield for a number of transmitantennas Nr=9 and for different numbers of Nc, i.e. spatial streamsranging from 1 to 9. The corresponding size of the feedback matrix V isalso depicted in FIG. 13 for the chosen parameters Nr=9 and Nc=1 to 9.Furthermore, a number of angles, Na, ranging from 16 to 72, is given intable T9, 1300.

FIG. 14 shows an exemplary angles definition table, T10, 1400illustrating the order of angles in the compressed beamforming feedbackmatrix subfield for a number of transmit antennas Nr=10.

The angles definition table, T10, 1400 defines the order of angles inthe compressed beamforming feedback matrix subfield for a number oftransmit antennas Nr=10 and for different numbers of Nc, i.e. spatialstreams ranging from 1 to 10. The corresponding size of the feedbackmatrix V is also depicted in FIG. 14 for the chosen parameters Nr=10 andNc=1 to 10. Furthermore, a number of angles, Na, ranging from 18 to 90,is given in table T10, 1400.

FIGS. 15 and 16 show an exemplary angles definition table, T11a, T11billustrating the order of angles in the compressed beamforming feedbackmatrix subfield for a number of transmit antennas Nr=11, the first partT11a, 1500 of the table is shown in FIG. 15 and the second part T11b,1600 of the table is shown in FIG. 16 .

The angles definition table, T11a, T11b defines the order of angles inthe compressed beamforming feedback matrix subfield for a number oftransmit antennas Nr=11 and for different numbers of Nc, i.e. spatialstreams ranging from 1 to 11. The corresponding size of the feedbackmatrix V is also depicted in FIGS. 15 and 16 for the chosen parametersNr=11 and Nc=1 to 11. Furthermore, a number of angles, Na, ranging from20 to 110, is given in table T11a, T11b.

FIGS. 17 and 18 show an exemplary angles definition table, T12a, T12billustrating the order of angles in the compressed beamforming feedbackmatrix subfield for a number of transmit antennas Nr=12 according to thedisclosure, the first part T12a, 1700 of the table is shown in FIG. 17and the second part T12b, 1800 of the table is shown in FIG. 18 .

The angles definition table, T12a, T12b defines the order of angles inthe compressed beamforming feedback matrix subfield for a number oftransmit antennas Nr=12 and for different numbers of Nc, i.e. spatialstreams ranging from 1 to 12. The corresponding size of the feedbackmatrix V is also depicted in FIGS. 17 and 18 for the chosen parametersNr=12 and Nc=1 to 12. Furthermore, a number of angles, Na, ranging from22 to 132, is given in table T12a, T12b.

FIGS. 19 and 20 show an exemplary angles definition table, T13a, T13billustrating the order of angles in the compressed beamforming feedbackmatrix subfield for a number of transmit antennas Nr=13 according to thedisclosure, the first part T13a, 1900 of the table is shown in FIG. 19and the second part T13b, 2000 of the table is shown in FIG. 20 .

The angles definition table, T13a, T13b defines the order of angles inthe compressed beamforming feedback matrix subfield for a number oftransmit antennas Nr=13 and for different numbers of Nc, i.e. spatialstreams ranging from 1 to 13. The corresponding size of the feedbackmatrix V is also depicted in FIGS. 19 and 20 for the chosen parametersNr=13 and Nc=1 to 13. Furthermore, a number of angles, Na, ranging from24 to 156, is given in table T13a, T13b.

FIGS. 21 and 22 show an exemplary angles definition table, T14a, T14billustrating the order of angles in the compressed beamforming feedbackmatrix subfield for a number of transmit antennas Nr=14 according to thedisclosure, the first part T14a, 2100 of the table is shown in FIG. 21and the second part T14b, 2200 of the table is shown in FIG. 22 .

The angles definition table, T14a, T14b defines the order of angles inthe compressed beamforming feedback matrix subfield for a number oftransmit antennas Nr=14 and for different numbers of Nc, i.e. spatialstreams ranging from 1 to 14. The corresponding size of the feedbackmatrix V is also depicted in FIGS. 21 and 22 for the chosen parametersNr=14 and Nc=1 to 14. Furthermore, a number of angles, Na, ranging from26 to 182, is given in table T14a, T14b.

FIGS. 23 and 24 show an exemplary angles definition table, T15a, T15billustrating the order of angles in the compressed beamforming feedbackmatrix subfield for a number of transmit antennas Nr=15 according to thedisclosure, the first part T15a, 2300 of the table is shown in FIG. 23and the second part T15b, 2400 of the table is shown in FIG. 24 .

The angles definition table, T15a, T15b defines the order of angles inthe compressed beamforming feedback matrix subfield for a number oftransmit antennas Nr=15 and for different numbers of Nc, i.e. spatialstreams ranging from 1 to 15. The corresponding size of the feedbackmatrix V is also depicted in FIGS. 23 and 24 for the chosen parametersNr=15 and Nc=1 to 15. Furthermore, a number of angles, Na, ranging from28 to 210, is given in table T15a, T15b.

FIGS. 25, 26 and 27 show an exemplary angles definition table, T16a,T16b, T16c illustrating the order of angles in the compressedbeamforming feedback matrix subfield for a number of transmit antennasNr=16 according to the disclosure, the first part T16a, 2500 of thetable is shown in FIG. 25 , the second part T16b, 2600 of the table isshown in FIG. 26 and the third part T16c, 2700 of the table is shown inFIG. 27 .

The angles definition table, T16a, T16b, T16c defines the order ofangles in the compressed beamforming feedback matrix subfield for anumber of transmit antennas Nr=16 and for different numbers of Nc, i.e.spatial streams ranging from 1 to 16. The corresponding size of thefeedback matrix V is also depicted in FIGS. 25, 26 and 27 for the chosenparameters Nr=16 and Nc=1 to 16. Furthermore, a number of angles, Na,ranging from 30 to 240, is given in table T16a, T16b, T16c.

FIG. 28 shows a schematic diagram of a method 2800 for requestingbeamforming information according to the disclosure.

The method 2800 comprises: transmitting 2801, by a beamformer device,e.g. beamformer device 110 shown in FIG. 1 , a request to a beamformeedevice, e.g. beamformee device 120 shown in FIG. 1 , the requestcomprising a set of sounding tone indices, the set of sounding toneindices indicating tones for which a report of beamforming informationis requested from the beamformee device, wherein the tones are definedaccording to a first WiFi scheme, wherein the set of sounding toneindices is based on a first tone plan defined by the first WiFi schemefor a partial channel bandwidth and on a second tone plan defined by asecond WiFi scheme for a full channel bandwidth.

The method 2800 further comprises: receiving 2802 the report ofbeamforming information from the beamformee device based on the set ofsounding tone indices.

The first tone plan may be defined as shown in FIG. 4 and the secondtone plan may be defined as shown in FIG. 2 .

The first WiFi scheme may be 802.11be WiFi, particularly supportingchannel bandwidths of 80 MHz, 160 MHz, 80+80 MHz, 240 MHz and 320 MHz.The second WiFi scheme may be 802.11ax WiFi, particularly supporting achannel bandwidth of 80 MHz.

FIG. 29 shows a schematic diagram of a method 2900 for reportingbeamforming information according to the disclosure.

The method 2900 comprises: transmitting 2901, by a beamformee device,e.g. beamformee device 120 shown in FIG. 1 , a report of beamforminginformation to a beamformer device, e.g. beamformer device 110 shown inFIG. 1 , based on a set of sounding tone indices received from thebeamformer device, wherein the set of sounding tone indices areindicating tones for which a report of beamforming information isrequested from the beamformee device, wherein the tones are definedaccording to a first WiFi scheme, wherein the set of sounding toneindices is based on a first tone plan defined by the first WiFi schemefor a partial channel bandwidth and on a second tone plan defined by asecond WiFi scheme for a full channel bandwidth.

The first tone plan may be defined as shown in FIG. 4 and the secondtone plan may be defined as shown in FIG. 2 .

This method corresponds to the beamformee device described above for thethird aspect of the disclosure.

The first WiFi scheme may be 802.11be WiFi, particularly supportingchannel bandwidths of 80 MHz, 160 MHz, 80+80 MHz, 240 MHz and 320 MHz.The second WiFi scheme may be 802.11ax WiFi, particularly supporting achannel bandwidth of 80 MHz.

FIG. 30 shows a schematic diagram of the Partial BW Info Field 3000. ThePartial BW Info Field 3000 comprises 6 bits B0-B5. The two leastsignificant bits 3001 (B0 and B1) of the Partial BW Info Field indicatethe type of partial BW, i.e. the resolution type. The four mostsignificant bits 3002 (B2, B3, B4 and B5) of the Partial BW Info Fieldindicate a specific BW corresponding the indicated partial BW type, theRU Index and/or a Segment Bitmap. It should be understood that also thetwo most significant bits (B4, B5) can indicate the resolution type,whereas the four least significant bits (B0, B1, B2, B3) can indicatethe specific BW corresponding the indicated partial BW type, the RUIndex and/or a Segment Bitmap.

FIG. 31 shows a schematic diagram of a modified STA Info Subfield 3100,wherein the bits B11-B16 have been replaced by the Partial BW Info Field3000.

The present disclosure also supports a computer program productincluding computer executable code or computer executable instructionsthat, when executed, causes at least one computer to execute theperforming and computing steps described herein, in particular themethods and procedures described above. Such a computer program productmay include a readable non-transitory storage medium storing programcode thereon for use by a computer. The program code may perform theprocessing and computing steps described herein, in particular themethods and procedures described above.

While a particular feature or aspect of the disclosure may have beendisclosed with respect to only one of several implementations, suchfeature or aspect may be combined with one or more other features oraspects of the other implementations as may be desired and advantageousfor any given or particular application. Furthermore, to the extent thatthe terms “include”, “have”, “with”, or other variants thereof are usedin either the detailed description or the claims, such terms areintended to be inclusive in a manner similar to the term “comprise”.Also, the terms “exemplary”, “for example” and “e.g.” are merely meantas an example, rather than the best or optimal. The terms “coupled” and“connected”, along with derivatives may have been used. It should beunderstood that these terms may have been used to indicate that twoelements cooperate or interact with each other regardless whether theyare in direct physical or electrical contact, or they are not in directcontact with each other.

Although specific aspects have been illustrated and described herein, itwill be appreciated by those of ordinary skill in the art that a varietyof alternate and/or equivalent implementations may be substituted forthe specific aspects shown and described without departing from thescope of the present disclosure. This application is intended to coverany adaptations or variations of the specific aspects discussed herein.

Although the elements in the following claims are recited in aparticular sequence with corresponding labeling, unless the claimrecitations otherwise imply a particular sequence for implementing someor all of those elements, those elements are not necessarily intended tobe limited to being implemented in that particular sequence.

Many alternatives, modifications, and variations will be apparent tothose skilled in the art in light of the above teachings. Of course,those skilled in the art readily recognize that there are numerousapplications of the invention beyond those described herein. While thepresent invention has been described with reference to one or moreparticular embodiments, those skilled in the art recognize that manychanges may be made thereto without departing from the scope of thepresent invention. It is therefore to be understood that within thescope of the appended claims and their equivalents, the invention may bepracticed otherwise than as specifically described herein.

1. A beamformer device comprises: a memory configured to storeinstructions; and a processor coupled to the memory and configured toexecute the instructions to cause the beamformer device: transmit arequest to a beamformee device, the request comprising a set of soundingtone indices, the set of sounding tone indices indicating tones forwhich a report of beamforming information is requested from thebeamformee device, wherein the tones are defined according to a firstWiFi scheme, wherein the set of sounding tone indices is based on afirst tone plan and a second tone plan, and wherein the first tone planis defined by the first WiFi scheme for a partial channel bandwidth, andthe second tone plan is defined by a second WiFi scheme for a fullchannel bandwidth.
 2. The beamformer device of claim 1, wherein thefirst WiFi scheme is 802.11be WiFi, and wherein the second WiFi schemeis 802.11ax WiFi.
 3. The beamformer device of claim 1, wherein the firstWiFi scheme is supporting channel bandwidths of 80 MHz, 160 MHz, 80+80MHz, 240 MHz and 320 MHz.
 4. The beamformer device of claim 1, whereinthe second WiFi scheme is supporting a channel bandwidth of 80 MHz. 5.The beamformer device of claim 1, wherein the full channel bandwidth is80 MHz, and wherein the partial channel bandwidth is any subset of thefull channel bandwidth.
 6. The beamformer device of claim 1, wherein thesounding tone indices are based on anew unified sounding index set thatcomprises sounding tone indices for both of (a) the first tone plan forthe partial channel bandwidth and (b) second tone plan for the fullchannel bandwidth.
 7. The beamformer device of claim 1, wherein thesounding tone indices are based on a new sounding index set for thepartial channel bandwidth and additional center tones indices for thefull channel bandwidth.
 8. The beamformer device of claim 1, wherein thesounding tone indices are based on a reuse of the sounding tone indicesdefined for resource units of the second tone plan and a definitionwhich resource units of the second tone plan correspond to resourceunits of the first tone plan.
 9. The beamformer device of claim 6,wherein the set of sounding tone indices for a channel bandwidth greaterthan the full channel bandwidth, and wherein the channel bandwidth isone of 160 MHz, 80+80 MHz, 240 MHz or 320 MHz, and is based on aduplication of rules defined for the set of sounding tone indices withineach segment of the full channel bandwidth.
 10. The beamformer device ofclaim 1, wherein the request to the beamformee device indicates achannel bandwidth, and wherein the indicated channel bandwidth is a fullchannel bandwidth defined for the first WiFi scheme.
 11. The beamformerdevice of claim 10, wherein the indicated channel bandwidth is a fullchannel bandwidth of 80 MHz, 80+80 MHz, 160 MHz, 240 MHz, 320 MHz or anypartial bandwidth thereof.
 12. The beamformer device of claim 1, whereinthe set of sounding tone indices is defined per channel bandwidth andper number of tones, wherein Ng=4 and Ng=16.
 13. A method for requestingbeamforming information, the method comprising: transmitting, by abeamformer device, a request to a beamformee device, the requestcomprising a set of sounding tone indices, the set of sounding toneindices indicating tones for which a report of beamforming informationis requested from the beamformee device, wherein the tones are definedaccording to a first WiFi scheme, wherein the set of sounding toneindices is based on a first tone plan and on a second tone plan; whereinthe first tone plan is defined by the first WiFi scheme for a partialchannel bandwidth, and wherein the second tone plan is defined by asecond WiFi scheme for a full channel bandwidth; and receiving thereport of beamforming information from the beamformee device based onthe set of sounding tone indices.
 14. A beamformee device comprising: amemory configured to store instructions; and a processor coupled to thememory and configured to execute the instructions to cause thebeamformee device to: transmit a report of beamforming information to abeamformer device based on a set of sounding tone indices received fromthe beamformer device, wherein the set of sounding tone indices areindicating tones for which a report of beamforming information isrequested from the beamformee device, wherein the tones are definedaccording to a first WiFi scheme, wherein the set of sounding toneindices is based on a first tone plan and a second tone plan, whereinthe first tone plan is defined by the first WiFi scheme for a partialchannel bandwidth, and wherein the second tone plan is defined by asecond WiFi scheme for a full channel bandwidth.
 15. A beamformer devicecomprising: a memory configured to store instructions; and a processorcoupled to the memory and configured to execute the instructions tocause the beamformer device to: receive a beamforming report from abeamformee device, wherein the beamforming report comprises a compressedprecoder matrix; and reconstruct a precoder matrix reported by thebeamformee device based on the compressed precoder matrix, wherein thecompressed precoder matrix is defined by a set of angles in a specificorder that implies a sequence of mathematical operations to be appliedon a unit matrix to reconstruct the precoder matrix, wherein the set ofangles is determined based on an extension of a given formula specifiedfor a number of transmit antennas and a number of spatial streamssupported by a second WiFi scheme, wherein the second WiFi scheme is802.11ax WiFi, to a number of transmit antennas (Nr) and a number ofspatial streams (Nc) supported by a first WiFi scheme, and wherein thefirst WiFi scheme is 802.11be WiFi.
 16. The beamformer device of claim15, wherein the extension of the formula is for values of 8<Nr≤16 andvalues of 1≤Nc≤16 corresponding to matrices from 9×1 to 16×16.
 17. Thebeamformer device of claim 15, wherein the beamforming report comprisessignal-to-noise ratio (SNR) values of spatial streams reported by thebeamformee device, and wherein each reported i-th SNR value, and whereini is an integer and i>8, corresponds to an SNR that results fromapplying an i-th column of the reported precoder matrix by thebeamformer device.
 18. The beamformer device of claim 17, wherein thebeamforming report comprises SNR values of spatial streams formultiple-input multiple-output (MIMO) schemes larger than 8×8.
 19. Abeamformer device comprising: a memory configured to store instructions;and a processor coupled to the memory and configured to execute theinstructions to cause the beamformer device to: transmit a request ofpartial bandwidth (BW), for sounding feedback to a beamformee device,the requested partial BW for sounding feedback comprising comprises apartial BW type, indicating the BW to be used for sounding feedback. 20.The beamformer device of claim 19, wherein the partial BW type is 20MHz, 40 MHz or n×80 MHz, wherein n is an integer equal or larger than 1.21. The beamformer device of claim 19, wherein the requested partial BWfor sounding feedback is comprised in a partial BW info field.
 22. Thebeamformer device of claim 21, wherein the partial BW info fieldcomprises 6 bits.
 23. The beamformer device of claim 21, wherein the 2least significant bits of the partial BW info field indicate the type ofpartial BW.
 24. The beamformer device of claim 21, wherein the 4 mostsignificant bits of the partial BW info field indicate a BWcorresponding the indicated partial BW type.
 25. The beamformer deviceof claim 19, wherein based on a partial BW type of 20 MHz beingsignaled, the 4 most significant bits of the partial BW info field ofthe partial BW info field indicate k-th RU242, where k is an integerequal or larger than 0, based on a partial BW type of 40 MHz basedsignaled, the 4 most significant bits of the partial BW info fieldindicate k-th RU484, wherein k is an integer from 1 to 8 or k-th RU242,based on a partial BW type of n×80 MHz being signaled, the 4 mostsignificant bits of the partial BW info field indicate a bitmap for 4segments of 80 MHz, wherein an indicated ‘1’ means 80 MHz is requestedfor sounding feedback.
 26. The beamformer device of claim 19, whereinbased on a partial BW type of 20 MHz being signaled, for indicated k-thRU242, tone indices defined for k RU242 are used, wherein k is aninteger equal or larger than 0, based on a partial BW type of 40 MHzbeing signaled, for indicated k-th RU484, tone indices defined for 2×kand 2×k+1 RU242 are used and for indicated k-th RU242, tone indicesdefined for k and k+1 RU242 are used, wherein k is an integer equal orlarger than 0, or based on a partial BW type of n×80 MHz being signaled,tone indices defined for 4*k, 4*k+1, 4*k+2, 4*k+3 RU242 are used,wherein n and k are integer equal or larger than 0.